package org.biblioteca.generales;

import java.io.UnsupportedEncodingException;
import java.security.spec.AlgorithmParameterSpec;
import java.security.spec.KeySpec;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.PBEParameterSpec;
import java.io.Serializable;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.SessionScoped;


/**
*
* @author avbravo
*/

/*
 ejemplo de uso
//Encriptador encrypter = new Encriptador("biblioteca");
// Encrypt
//String encrypted = encrypter.encrypt("texto a encriptar");
System.out.println("Encriptado: " + encrypted);
// Decrypt
 String decrypted = encrypter.decrypt(encrypted);
 System.out.println("Desencriptado: " + decrypted);

 */ 
@ManagedBean
@SessionScoped
public class Encriptador implements Serializable {
   private static final long serialVersionUID = 1L;


   Cipher ecipher;
   Cipher dcipher;
   // 8-byte Salt
   byte[] salt = {
                  (byte) 0xA9, (byte) 0x9B, (byte) 0xC8, (byte) 0x32,
                  (byte) 0x56, (byte) 0x35, (byte) 0xE3, (byte) 0x03
                 };
   // Iteration count
   int iterationCount = 19;
   public Encriptador(String passPhrase) {
    try {
       //   String passPhrase = sesion.getFaseEncriptacion();
      // Create the key
       KeySpec keySpec = new PBEKeySpec(passPhrase.toCharArray(), salt, iterationCount);
       SecretKey key = SecretKeyFactory.getInstance(
              "PBEWithMD5AndDES").generateSecret(keySpec);
        ecipher = Cipher.getInstance(key.getAlgorithm());
        dcipher = Cipher.getInstance(key.getAlgorithm());
     // Prepare the parameter to the ciphers
         AlgorithmParameterSpec paramSpec = new PBEParameterSpec(salt, iterationCount);
    // Create the ciphers
         ecipher.init(Cipher.ENCRYPT_MODE, key, paramSpec);
         dcipher.init(Cipher.DECRYPT_MODE, key, paramSpec);
     } catch (java.security.InvalidAlgorithmParameterException e) {
  } catch (java.security.spec.InvalidKeySpecException e) {
  } catch (javax.crypto.NoSuchPaddingException e) {
  } catch (java.security.NoSuchAlgorithmException e) {
  } catch (java.security.InvalidKeyException e) {
    }
  }
  public String encrypt(String str) {
  try {
      // Encode the string into bytes using utf-8
        byte[] utf8 = str.getBytes("UTF8");
      // Encrypt
       byte[] enc = ecipher.doFinal(utf8);
      // Encode bytes to base64 to get a string
        return new sun.misc.BASE64Encoder().encode(enc);
 } catch (javax.crypto.BadPaddingException e) {
 } catch (IllegalBlockSizeException e) {
 } catch (UnsupportedEncodingException e) {
 } catch (java.io.IOException e) {
 }
    return null;
 }
   public String decrypt(String str) {
    try {
        // Decode base64 to get bytes
        byte[] dec = new sun.misc.BASE64Decoder().decodeBuffer(str);
        // Decrypt
        byte[] utf8 = dcipher.doFinal(dec);
        // Decode using utf-8
       return new String(utf8, "UTF8");
     } catch (javax.crypto.BadPaddingException e) {
 } catch (IllegalBlockSizeException e) {
   } catch (UnsupportedEncodingException e) {
   } catch (java.io.IOException e) {
   }
    return null;
 }
}
